TypeScript abstract method using lambda/arrow function
My understanding of Typescript specifications is that when you are declaring
public def = (): void => { this.setting = false;}You are actually declaring a property called def and not a method on the Base class.
Properties cannot (unfortunately IMHO) be abstracted in Typescript: https://github.com/Microsoft/TypeScript/issues/4669
You can use an abstract property:
abstract class Base { abstract def: () => void; // This is the abstract property}class Concrete extends Base { private setting: boolean; public def = (): void => { this.setting = false; }}var myVar: Base = new Concrete();myVar.def();console.log((myVar as any).setting); // gives false
You could do that starting typescript 2.0. In order to make that work you would need to declare a type for your arrow function
type defFuntion = () => void;then declare
abstract class Base { abstract abc(): void; abstract readonly def: defFuntion;}here is a reference for this feature